Description: Solid state, class-A/AB stereo/bridged mono power amplifier. Inputs: 1 pair single-ended (RCA), 1 pair balanced (XLR). Outputs: 2 pair loudspeaker binding posts. Rated output power, stereo: 150Wpc continuous into 8 ohms (21.8dBW), 250Wpc into 4 ohms (21dBW). Rated output power, mono: 450W continuous into 8 ohms (26.5dBW), 600W into 4 ohms (24.8dBW). Frequency response: 20Hz–20kHz, ±0.5dB, –3dB at 70kHz. Distortion: <0.03% THD at rated output power. Output current: 50A per channel for short durations, fuse protected. Input impedance: 47k ohms. Hum…
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Sidebar 2: Associated Equipment
Digital sources: dCS Vivaldi Apex DAC, Vivaldi Upsampler Plus, Vivaldi Master Clock; Innuos Statement Next-Gen Music Server; Small Green Computer Sonore Deluxe opticalModule; Uptone Audio EtherRegen with SOtM sCLK-OCX10 Master Clock and sPS-500 power supply; Nordost QSource linear power supplies (2); HDPlex 300 linear power supply; Synology 5-bay 1019+ NAS powered by Ferrum Hypsos linear/switching hybrid power supply; Linksys mesh router and Arris modem; 2017 Apple iPad Pro, 2017 MacBook Pro laptop with 2.8GHz Intel i7, SSD, 16GB RAM.
Preamplifier: Dan…
Sidebar 3: Measurements
I used my Audio Precision SYS2722 system for the testing. I performed complete sets of measurements on one of the Plinius A-150s that had been auditioned by JVS (serial number 8797) in both class-AB and class-A stereo modes. I then repeated the testing with the A-150 in bridged-mono mode. I preconditioned the A-150 in class-AB mode by following the CEA's recommendation of running it at one-eighth the specified power into 8 ohms for 30 minutes. At the end of that time, the temperature of the top panel was 90.7°F (32.6°C) and that of the side-mounted heatsinks 90.1°F…
The review gear piles up, and it's time for a late spring cleaning—not that any dust has gathered on the uniformly excellent products covered in this column. I'll start with two very different phono cartridges.
Ikeda Sound Labs 9mono moving-coil cartridge: $4400
The Ikeda Sound Labs 9mono cartridge ($4400, above; footnote 1) is a dedicated mono design intended to integrate well into a modern stereo system. Within its curved body, made of solid aluminum alloy, is a low-output (0.22mV) moving-coil motor with a very low internal impedance (2.0 ohms). Generally, both specs mean fewer coil…
Sound: Once set up and loaded at about 200 ohms using the Ypsilon MC-10L step-up transformer, with no resistors in the Ypsilon's loading jacks, the Crimson XGW produced sound unlike that of any other vdH cartridge I've reviewed. I'm preconditioned to the lightning-fast—some would say threadbare—excitement of vdH's tightly sprung Colibri and Grasshopper cartridges; the sound of the Crimson XGW was precisely the opposite: it was a warm, sweet, and well textured performance—and yet, arguably because of the stylus profile, it was well-detailed, as well.
Rather than play familiar…
John Atkinson reviewed the DC1 DAC module in February 2024 (Vol.47 No.2):
I concluded my September 2023 review of this tubed integrated amplifier by writing that the Audio Research I/50 "is the perfect amplifier for use in a relatively small room with a high-quality source and speakers, especially if the latter have a fairly high impedance. The I/50 has a touch of that 'tube magic' but without going whole hog, as so many of the current crop of tubed amplifiers do." The review sample just had balanced and single-ended line inputs and costs $5500, but toward the end of the review period I…
Three products were recently subjected to second opinions: I reviewed the revised RS250A version of HiFi Rose's RS250 streaming D/A preamplifier and the optional DC1 DAC module for Audio Research's I/50 integrated amplifier; Ken Micallef wrote about his time with the Volti Razz loudspeaker.
I reviewed the original HiFi Rose RS250 in December 2021. I wrote that this is "an extraordinarily versatile, affordable product" and that its sound quality suggested that nothing had been compromised in packing so many features into its small chassis. "Highly recommended," I concluded, "both as a…
Changing his tune: Rogier van Bakel's listening room shortly after demolition began. The space had been an old two-car garage. (All photos by Rogier van Bakel.)
As happy moments in one's life go, this one was supposed to be up there: the time I first heard my stereo rig in the new, custom-built listening room in the back of my home. It had taken eight months to get to this point, starting with gutting the garage and rebuilding the floor and walls. (We kept the roof.) By the end, all-new doors and windows had been hung and treated with acoustical sealant. Extra-thick drywall and mass-…
In trying for a balance between pleasant living space and audiophile lair, I made a few other deals with the devil. For instance, there are no audiophile-approved audio racks in my room. I'd have needed nine or 10 shelves—two racks, give or take. Aside from the expense, high-end racks would've given less of a "livable" vibe to the room, so I'm happy I found the equipment console I mentioned. For the best sound, it should probably be closer to me, along one of the two long sides of the room, but for various reasons, this proved impractical. I ultimately put the console about 2' from the…
Weinberg: Dawn, Op.60, Symphony No.12, Op.114
BBC Philharmonic, John Storgårds, cond.
Chandos 20165 (CD, reviewed as 24/96). 2023. Brian Pidgeon, Mike George, prods.; Stephen Rinker, eng.
Performance ****
Sonics ****
BBC Philharmonic, John Storgårds, cond.
Chandos 20165 (CD, reviewed as 24/96). 2023. Brian Pidgeon, Mike George, prods.; Stephen Rinker, eng.
Performance ****
Sonics ****
Warsaw-born Mieczysław Weinberg, whose parents worked in the Yiddish Theater and died in a Nazi concentration camp, began a close friendship with Shostakovich. Citing their meeting as the time his life was born anew, Weinberg shared with Shostakovich a history of persecution by Soviet authorities. Shostakovich championed Weinberg's work and interceded on his…